How do we know that Christ is successful in saving us?

The success of Christ in salvation lies in His accomplished work on the cross, where He bore the wrath of God for the sins of His people. As stated in Matthew 1:21, Jesus came to save His people from their sins. When He said, 'It is finished' (John 19:30), He signified that He had successfully completed the work of redemption, satisfying divine justice. Therefore, no one who relies on Christ's work will ever be turned away. This assurance is foundational for believers, knowing that their acceptance before God is secured through Christ's sufficiency and His successful fulfillment of the law.